CN1050463C - Lens barrel for a video camera, and linear feeding system therefor - Google Patents
Lens barrel for a video camera, and linear feeding system therefor Download PDFInfo
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- CN1050463C CN1050463C CN95105150A CN95105150A CN1050463C CN 1050463 C CN1050463 C CN 1050463C CN 95105150 A CN95105150 A CN 95105150A CN 95105150 A CN95105150 A CN 95105150A CN 1050463 C CN1050463 C CN 1050463C
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
- H02K41/02—Linear motors; Sectional motors
- H02K41/035—DC motors; Unipolar motors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
- G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
- G01D5/245—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains using a variable number of pulses in a train
- G01D5/2451—Incremental encoders
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
- G02B7/04—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
- G02B7/10—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification by relative axial movement of several lenses, e.g. of varifocal objective lens
- G02B7/102—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification by relative axial movement of several lenses, e.g. of varifocal objective lens controlled by a microcomputer
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
- H02K41/02—Linear motors; Sectional motors
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Electromagnetism (AREA)
- Power Engineering (AREA)
- Linear Motors (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
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Abstract
A linear feeding system comprises a DC motor with brush, a lead screw integrally arranged as the rotational shaft of the DC motor, and a nut member screwed on the lead screw. This linear feeding system further comprises a magnet installed on the rotational shaft of the DC motor, which is provided with a plurality of N-pole and S-pole magnets being magnetized alternately in the circumferential direction, and a magnetoresistive effect sensor fixedly arranged to face this magnet. With this structure, it is possible to provide a simply structured, small linear feeding system capable of performing a high precision high-speed feeding operation at low costs.
Description
The present invention relates to the lens barrel of TV camera, and used linear feeding system.Specifically, the present invention relates to the lens barrel of TV camera and be used for the zoom lens propulsive mechanism or be used for the linear feeding system of TV camera lens barrel.
In general, this linear feeding system adopts the DC motor of charged brush or stepping motor as its actuating force.
In the above-mentioned linear feeding system, there is a kind of its power source outside being coupled the system of optical encoder, its objective is the rotation of controlling power source accurately.
But such linear feeding system has run into following problem:
For as mentioned above as power source the brush DC motor arranged, system should adopt transmission mechanism reduce its rotating speed when keeping the direct current machine high speed rotating.
In addition, in this system, adopt transmission mechanism can cause the backlash phenomenon, this must make the precise decreasing of propelling.This problem is more serious in all problems.
And when using direct current machine as the system dynamic source, and when wherein motor being controlled with optical encoder, will run into another problem, that is: this encoder should be installed in outside and it is positioned at accurately and be coupled on the position, and this will improve the expense of parts and assembling.
And, also having a problem, the torque of dc micro-motor does not allow directly to be coupled the external optical encoder and controls motor.
On the other hand, then also there are some problems in the source if the employing stepping motor is used as power, and one of them is because its operation control is open loop, so the precision of stop position is lower.And adopt stepping motor to be difficult to find the generation of synchronous mistake, break down in some cases.Especially when stepping motor is done small stepping, during a complete stepping period, can't know the position that parts are pushed into, so be difficult to realize accurate location.
In order to address the above problem, to the purpose of this invention is to provide a kind of TV camera lens barrel and a kind of linear feeding system, thereby can carry out high-precision propelling with the small-sized easy structure of making than lower cost.
In order to realize purpose of the present invention, linear feeding system includes power source, the screw rod that becomes one with the power source rotation axis, be screwed in the nut component on the screw rod, but also include a magnet that is contained in the power source rotating shaft, the N-utmost point and the S-utmost point that this magnet along the circumferential direction alternately has magnetization to come out, and magnetoresistive effect sensor is fixed on the opposite of magnet.
In said structure, along the circumferencial direction of the tubular of installing in the power source rotating shaft, cylindricality or disc magnet, the magnetic field of the N-utmost point and the S-utmost point alternately distributes.When the magnetoresistive effect sensor of these magnetic field versus in the magnet opposite plays a role, then can detect the rotation direction and the speed of power source.
Therefore, the spacing according to each magnetic pole of magnet can accurately detect the position.
Above-mentioned purpose of the present invention, feature and advantage will be by becoming clearer below in conjunction with the accompanying drawing detailed description of the invention.Wherein,
Fig. 1 is the end view of an embodiment of expression linear feeding system of the present invention;
Fig. 2 is the end view of expression linear feeding system rotating shaft shown in Figure 1 and magnet;
Fig. 3 is the local enlarged perspective that concerns between magnet and the magnetic group effect sensor in the expression linear feeding system shown in Figure 1;
Fig. 4 is the schematic diagram that concerns between an expression magnetic flux of each magnetic pole and the magnetoresistive effect sensor;
Fig. 5 is the curve chart of the various outputs of magnetoresistive effect sensor of an expression linear feeding system shown in Figure 1;
Fig. 6 is the amplification view of the magnetoresistive effect sensor graphic structure of an expression linear feeding system shown in Figure 1;
Fig. 7 is the schematic diagram of an expression magnetoresistive effect sensor equivalent electric circuit shown in Figure 6;
Fig. 8 is the block diagram of an expression magnetoresistive effect sensor circuit structure shown in Figure 6;
Fig. 9 is control is implemented in an expression according to the counting of a calculator shown in Figure 8 block diagram;
Figure 10 is the end view of another embodiment of linear feeding system of the present invention;
Figure 11 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 12 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 13 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 14 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 15 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 16 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetic resistance induction sensor;
Figure 17 is its magnet of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 18 is its magnetic field of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 19 is its magnetic field of linear feeding system of an expression a preferred embodiment of the present invention and the assembly structure example schematic of magnetoresistive effect sensor;
Figure 20 A to 20C is the schematic diagram of the gap adjustment structure example of expression its magnetic field of linear feeding system of a preferred embodiment of the present invention and magnetoresistive effect sensor;
Figure 21 A to 21C is its magnetic field of linear feeding system of expression a preferred embodiment of the present invention and the overall schematic of magnetoresistive effect sensor gap adjustment structure example;
Figure 22 is its magnetic field of linear feeding system of expression a preferred embodiment of the present invention and the schematic diagram of magnetoresistive effect sensor gap adjustment structure example;
Figure 23 is its magnetic field of linear feeding system of expression a preferred embodiment of the present invention and the schematic diagram of magnetoresistive effect sensor gap adjustment structure example;
Figure 24 is one and has represented to include the example dissection perspective view of the TV camera lens barrel of linear feeding system of the present invention with the zoom lens propulsive mechanism.
Hereinafter, will describe the preferred embodiment of the present invention in detail referring to figs. 1 to 24.
Following embodiment is a kind of concrete preferred embodiment of the present invention.Therefore, explanation will be subjected to various restrictions aspect the technical description.But scope of the present invention is not subjected to the restriction of those embodiments, unless hereinafter in the specification specified otherwise is arranged in addition.
Fig. 1 is the accompanying drawing of an a kind of embodiment of expression linear feeding system of the present invention.
In Fig. 1, linear feeding system 10 has a charged brush direct current machine 11; A screw rod 12 formulated together with the rotating shaft 11a of direct current machine 11; A nut component 13 that is screwed on the screw rod; A magnet 14 that is installed on the direct current machine 11 rotating shaft 11a, and this magnet has the along the circumferential direction alternatively distributed N-utmost point and the S-utmost point; One is fixed on magnet 14 opposites and carries out the magnetoresistive effect sensor 15 that angle detects; Reach one and be used for testing the endpoint sensors 16 whether nut component 13 arrives screw rod 12 left ends among Fig. 1.In this embodiment, the output of endpoint sensors 16, tracked when nut assembly 13 leans on upper extreme point transducer 16.
Direct current machine 11 its structures of charged brush are known.When the external dc electric current, rotating shaft 11a is driven and rotates.
Screw rod 12 by directly on Fig. 1 rotating shaft 11a cutting thread obtain.But also can install to a screw rod on the rotating shaft 11a by modes such as interference fit, threaded engagement.
Nut assembly 13 is screwed on the screw rod 12, so that it can do rectilinear motion along the direction shown in the arrow by the rotation of screw rod 12.Meanwhile, nut assembly is being coupled and is wanting driven parts (not shown).In the method,, driven parts are also moved in the direction shown in the arrow along with the rectilinear motion of nut assembly 13 in direction shown in the arrow.Here, driven parts are TV camera lens barrel scaffolds, the framework of a supporting condenser lens, the perhaps scaffold of an optics stylus.
Shown in Figure 1, magnet 14 is discoidal, but it can be a cylindricality or barrel-shaped.As long as magnet encloses direction a plurality of magnetic poles that distributing along circle, just can be used for other embodiments.
In addition, the N-utmost point of magnet 14 and the S-utmost point along the circumferential direction are alternately distributed as shown in Figure 3.
The operation principle of magnetoresistive effect sensor 15 is described now.Shown in Fig. 4 the first half, magnetoresistive effect sensor 15 is placed facing to magnet, and this magnet has the N utmost point and the S utmost point of alternately arranging with the magnet pole widths of going into, to form the striated structure of λ/2 width.
The two ends of this striated structure connect constant voltage Vcc and ground wire GND respectively, obtain the midpoint potential Vs (see figure 6) of striated structure then from A and B output.
Shown in Fig. 4 the latter half, when magnet 14 when direction shown in the arrow is moved, can obtain the midpoint potential Vs of one-period sine or quasi sine waveform from magnetoresistive effect sensor 15, this midpoint potential Vs is corresponding to concerning that with this transducer 15 and magnet 14 phase positions corresponding to is a magnet pole widths λ of mid point with Vcc/2.
When magnetoresistive effect sensor 15 had two to stagger the candy strip of λ/4 each other, then the output of magnetoresistive effect sensor 15 each candy strip was expressed as sine wave and cosine wave respectively, and its mid point all is Vcc/2 shown in Fig. 5 the first half.These waveforms can be represented with following formula (1) and (2):
A·Sinθ+Vcc/2 ···(1)
ACos θ+Vcc/2 (2) in the case, the structure of magnetoresistive effect sensor 15 is as shown in Figure 6.
In Fig. 6, the striped of magnetoresistive effect sensor on the Vcc limit and GND limit, with respect to magnet pole widths λ λ/2 that are separated from each other, and two adjacent pattern each interval λ/4 simultaneously.
For these candy strips, can provide the equivalent electric circuit of magnetoresistive effect sensor 15 as shown in Figure 7.Resistance R
1And R
2, R
3And R
4Identical resistance is arranged respectively.
These resistance R
1And R
2, R
3And R
4Resistance, since magnet shown in Figure 4 14 positions former thereby when causing the effective magnetic field Strength Changes will change.Consequently, it is A Sin θ and the A Cos θ of Vcc/2 that the output of output terminals A and B becomes respectively with the corresponding midrange in the position of magnet 14, shown in Fig. 5 upper curve.
On the other hand, resistance R
5And R
6Be positioned over the position of no the action of a magnetic field.And output SO always exports a constant voltage Vcc/2, and with the location independent of magnet 14.
Fig. 8 has represented the electric structure of linear feeding system shown in Figure 1.
In Fig. 8, linear feeding system 10 comprises, first comparator 21 that its reverse input end and input in the same way link to each other with SO with magnetoresistive effect sensor 15 output terminals A respectively; Second comparator 22 that its reverse input end and input in the same way link to each other with SO with magnetoresistive effect sensor 15 output B respectively; Comparator 21 and 22 output be the input phase discriminator 23 that links to each other with it; The tracer 28 of receiving terminal point sensor 16 output signals; Receive the up-down counter 24 of phase discriminator 23 and tracer 28 output signals; And the register 24a of receiving locus detector 28 output signals.
Subsequently, the signal of up-down counter 24 and register 24a output is admitted to CPU25, and CPU25 comes Control Driver 27 by digital to analog converter 26.
By applying the rotation of certain speed for magnet 14, magnetoresistive effect sensor 15 picks out the traffic direction and the speed of nut assembly 13, and the rotation of nut is to be determined by rotation direction and the speed of rotating shaft 11a.
Up-down counter 24 detects the angle of direct current machine 11 rotating shaft 11a by to the rising pulse or fall pulse and count of phase discriminator 23 output.
CPU25 calculates the angle-data (present value) of rotating shaft 11a according to the count value of up-down counter 24 outputs.According to above-mentioned gained angle-data with for reaching the poor of angle (desired value) that moving-member desired location rotating shaft 11a should change, CPU provides a drive command value.
In this case, CPU25 is according to the count value of up-down counter 24 shown in Figure 9, make comparisons with the current position (present value) in the external position loop being moved the position (desired value) that parts will reach, and, finish relatively and control by multiply by the position proportional gain with this difference.
And CUU25 is the acquisition speed value from the differential data of interior speed loop count value, and speed data and position loop gained result are made comparisons, thereby carries out the control of ratio difference according to comparing the gained difference.
Thus, CPU25 converts the result of proportional control and the control of ratio difference to analog signal by means of digital to analog converter 26, and it is outputed to driver 27.Driver 27 in buffer storage, and provides electric current analog signal storage for motor 11.
So, in Fig. 9, make calculating with following formula (3), wherein the position proportional gain is Kp; The speed differential gain is K1; The speed proportional gain is K2; Laplacian is S; The motor torque constant is Rt; Motor inertia is j, and speed term is D.
K
1/ S+K2 (2) so, the direct current machine 11 that is driven by it device 27 control can have:
Kt/ (Js+D) (4) and count value after moving can be obtained by following formula,
1/S ···(5)
The linear feeding system 10 of the present embodiment has structure as mentioned above, and direct current machine 11 is subjected to the drive controlling of driver 27 via digital to analog converter 26 and rotates,
Thus, rotating shaft 11a rotates, and causes the nut assembly 13 that is screwed on the rotating shaft 11a screw rod 12 can moving axially along rotating shaft 11a.
Figure 10 has represented second embodiment of linear feeding system of the present invention.
In Figure 10, linear feeding system 40 comprises: a screw rod 42 that constitutes one as 41, one of the stepping motors of its power source and the rotating shaft 41a of stepping motor 41; A nut 43 that is screwed on the screw rod 42; A magnet 44 that is contained on the stepping motor 41 rotating shaft 41a, this magnet along the circumferential direction alternately is distributed with the N-utmost point and the S-utmost point; The magnetoresistive effect sensor 45 that is positioned magnet 14 opposites that detection angles is used; One put with the screw rod end of stepping motor 41 opposite ends near endpoint sensors 46, this transducer is used for detecting nut assembly 43 and whether has arrived Figure 10 screw rod left end portion.
Stepping motor 41 has following structure:
In Figure 10, bearing support 56 the extending axially of stepping motor 41 along machine shaft.Its cross section vertically has and resembles the shape of opening shown in Figure 10 to upper frame.In an end of bearing support 56, fixing a shell spare 51.
In shell spare 51, cylindrical core assembly (stator) 52 is housed.Core assembly 52 is by being constituted by 4 groups of dentation iron cores of resin casting all-in-one-piece.On core assembly 52, can be around two groups of coil 53a and 53b.Around it is peripheral, be covered with shell spare 51.
And by being fixed on the rotor 55 that magnet 54 constitutes on the rotating shaft 41a in the installed inside of this core assembly 52.Around magnet 54, exist the given slit G between magnet and core assembly 52 inner circumferential surfaces.Therefore, utilize the rotating magnetic field that electric current produced that change is sequentially flow through among coil 53a and the 53b that rotating shaft 41a is rotated.
Except power source 11 adopts in the present embodiment the stepping motor, the structure of the present embodiment is identical with first embodiment.But because the open loop of stepping motor control, the digital to analog converter 26 of the direct current machine in the circuit then shown in Figure 8 has become pre-driver, thereby the signal that advances instruction as a small stepping is transported to driver from CPU.
With reference now to the Figure 11 that has represented the various variations of major part, to Figure 23, illustrates with the linear feeding system all kinds of stepping motor as power source.
The linear feeding system 60 that Figure 11 represents is a kind of structures that magnet 67 is installed in machine shaft 61 1 ends, and this rotating shaft is extended in bearing support 63.In the example of Figure 11, magnet 67 is between bearing support 63 inner screws 62 and motor casing 64.
Therefore, if bearing support 63 design rightly in advance, moulding of can utilizing then that synthetic resin the constitutes center that part makes bearing support 63 with respect to rotating shaft 61 vertically and axle center O accurately locate.
Therefore,, there is the load module 66 of a given thickness to be fixed on the bearing support 63, then between magnet 67 circuital magnetizations surface and magnetoresistive effect sensor 67, a suitable slit just can be arranged as long as magnetoresistive effect sensor 65 adopts as Figure 11.
Therefore, can be placed in the position that magnet can produce suitable magnetic density to magnetoresistive effect sensor 65 easily according to the magnetization situation of magnet.
Linear feeding system 70 shown in Figure 12 has such structure: bearing support 73 has bigger size, and the motor casing 74 of stepping motor is installed within this bearing support.In this linear feeding system 70, magnetoresistive effect sensor 75 also installs in the bearing support 73 by load module 76.
And, situation as shown in figure 11, magnetoresistive effect sensor 75 can be fixed together with the bearing support 73 of standard, makes it can suitably determine distance between magnet 67 and the transducer.
Consequently, face on the position of this magnet 87, just can obtain the effect identical with situation shown in Figure 11 as long as magnetoresistive effect sensor 85 is fixed in the bearing support 83 as shown in figure 13.
For this linear feeding system,, must the left end from Figure 13 insert rotating shaft and pass bearing support and enter in the motor casing in when assembling.But to the described linear feeding system of Figure 11 to 13, magnet all is positioned at the left side of motor casing.So during rotating shaft, rotating shaft will allow magnet remain on the position of regulation when inserting bearing support in assembling, and magnet should be positioned at the position that allows rotating shaft can pass motor casing after passing, to finish assembling process.
Here, among Figure 14 and Figure 15, magnet 97 and 117 all assembles and is fixed on front end one side of rotating shaft 91 and 111 respectively.Thus, each rotating shaft 91 and 111 can be passed bearing support 93 and 113 and motor casing 94 and 114 earlier, passes magnet 97 and 117 more at last.This structure is convenient to assembling.
In this case, the bearing support 93 of the linear feeding system shown in Figure 14 and 15 and 113 intermediate portions all bend.For these linear feeding systems 90 and 110, magnetoresistive effect sensor 95 is the same with the situation with Figure 11 shown in 15 as Figure 14 with 115, is fixed on the bearing support and holds the corresponding part in position of magnet 97 and 117.Therefore can obtain the effect identical with linear feeding system shown in Figure 11 60.
In Figure 16, magnet 127 is fixed on the left end of linear feeding system 120 rotating shafts 121.Therefore, the same with Figure 14 and situation shown in Figure 15, assembling has been become easily.For the linear feeding system 130 of Figure 17, magnet is fixed on the right-hand member of rotating shaft 131.So, can obtain the effect identical with linear feeding system shown in Figure 16 120.
In situation shown in Figure 16, magnetoresistive effect sensor 125 fixes in this manner, that is: have the fixation kit 128 of turning cross sectional shape to be arranged on the bearing support 123, and load module 126 is fixed thereon, and uses load module 126 fixation of sensor then.
In situation shown in Figure 17, magnetoresistive effect sensor 135 is fixing in such a way, promptly; Have the fixation kit 138 in L shaped cross section to be arranged on the motor casing 134, and load module 136 is fixed thereon, and uses this load module 136 fixation of sensor then.
Figure 18 has represented the another kind of modification of linear feeding system.
In Figure 18, linear feeding system 140 is made up of following structure: a bearing support 143 is set, and screw rod 142 ends and motor casing 144 ends are separated, and the front end of rotating shaft 141 couples at coupling part 141b place with methods such as welding.So mode can suitably be selected the screw rod 142 of different pitch, and be fixed to motor main body one end.This structure has fabulous adaptability.
In this case, magnetoresistive effect sensor 145 is fixing as follows, and load module 146 is arranged on the fixation kit 148 that is fixed on the motor casing 144, and transducer is fixed in the load module 146 then.
For linear feeding system shown in Figure 19 150, screw rod 152, bearing support 153 and motor casing 154 all are arranged on the left side among Figure 19.By a coupling part 151b, another rotating shaft 151a is connected with the front end of rotating shaft 151.Magnet 157 is fixed on this rotating shaft 151a.This rotating shaft 151a is inserted in the independent fixation kit 158 that is provided with.On the lower surface of this fixation kit 158, magnetoresistive effect sensor 155 is fixed on magnet 157 opposites by a load module 156.
For linear feeding system 150, also can be as situation shown in Figure 180, another kind of magnet and the miscellaneous part appropriate combination that different size is arranged.This structure also has extremely wide adaptability.
Therefore, Figure 11 can be at its focal length screw thread of getting on the bus out to the rotating shaft of linear feeding system shown in Figure 19, thinks that it makes screw rod.Certainly, also can be at its whole length its screw rod of getting on the bus out.
Figure 20 A has represented the example of adjusting desired structure in slit between a kind of magnetoresistive effect sensor and magnet to 20C.
Figure 20 A is the front view of its critical piece, and Figure 20 B is its bottom view.Figure 20 C is an end view.This slit adjustment structure is applicable to the assembly structure of magnetoresistive effect sensor shown in Figure 14.Figure 20 A and Figure 20 C express the element situation from Figure 14 reverses direction, and purpose is to be convenient to explanation.
In Figure 20 A and Figure 20 C, load module 161 comprises the horizontal component 161a that is fixed on the bearing support 93, from the vertically extending vertical component 161b of the end of horizontal component 161a.Magnetoresistive effect sensor 95 is fixed on vertical component 161b in the face of on the side surface of magnet 97.One projection 163 is arranged on the bottom surface of horizontal component 161a, and it is inserted on the bearing support 93 and is pre-formed in the pilot hole.On the end of horizontal component 161a and projection 163 opposite sides, shown in Figure 20 B, be provided with the slotted hole 164 that is R shape basically.This structure can make the projection 93a on bearing support 93 upper surfaces cooperate with slotted hole 164.
Use this structure, in slotted hole 164, relatively move, and allow load module 96 rotate around projection 163 along direction shown in the arrow by making projection 93a.Thus, be fixed in the load module 96 magnetoresistive effect sensor 95 can near or away from magnet 97.So can regulate the slit between magnetoresistive effect sensor 95 and the magnet 97,, can be fixed on the horizontal component 161a of load module 96 on the bearing support 93 with method such as bonding so that after the position that chooses suitable magnetic density.
Figure 21 has represented another example of slit adjustment structure between magnetoresistive effect sensor and magnet.In this example, magnet 97 is different from the situation shown in Figure 20 with the orientation of magnetoresistive effect sensor 95, but other all parts all with Figure 20 in identical.
Figure 22 has represented another example of slit adjustment structure between magnetoresistive effect sensor and magnet.
Critical piece when Figure 22 has represented that bearing support shown in Figure 11 63 and magnetoresistive effect sensor 65 are fixed together.Load module 66 can comprise the first load module 66a and the second load module 66b.The upper surface of the first load module 66a is made into a kind of skewed surface 66c, and is fixing the second load module 66b on this skewed surface 66c.Magnetoresistive effect sensor 65 is fixed on this second load module 66b.
When the second load module 66b along direction shown in the arrow on inclined-plane 66c when mobile, therefore the slit between magnetoresistive effect sensor 65 and the magnet 67 can dwindle or widen.Thus, can be positioned on the suitable position of magnet 67 magnetic densities, thereby the second load module 66b can be fixed on the first assembly 66a with method such as bonding facing to the magnetoresistive effect sensor 65 of magnet 67.
Figure 23 has represented the critical piece of stepping motor shown in Figure 10, and wherein the manufacturing process of magnet is different.
In this embodiment, rotor magnet 245 and displacement detecting magnet 244 constitute one.In other words, along distributing on the rotor magnet 245 that alternately is distributed with the N-utmost point and the S-utmost point on its circumferencial direction coil 53a and 53b.Displacement detecting magnet 244 constitutes one with rotor magnet 245, is that it crosses the part that constriction 242 continues extension.The diameter of displacement detecting magnet 244 is bigger than rotor magnet.Displacement detecting magnet 244 along the circumferential direction has the alternatively distributed N-utmost point and the S-utmost point, and it is different from the spacing of rotor magnet 245 alternating poles at interval.
Therefore,, can assemble up rotor magnet 245 and displacement detecting magnet 244, and simultaneously they are fixed on the rotating shaft 241a, be convenient to assembling like this for the present embodiment.And because the existence of the constriction 242 between rotor magnet 245 and the displacement detecting magnet 244, even its Distribution of Magnetic Field is inequality, the different magnetic field of these two magnet can not interact yet.
Figure 24 is the perspective view of a decomposition, and it has represented to make lens barrel used in the TV camera of its varifocus objective propulsion system with the present embodiment linear feeding system.
In Figure 24, the lens barrel 30 that TV camera is used comprises successively: the object lens framework 31 of supporting lens sheet; Second cell mount 32; Diaphragm frame 33, the three cell mounts 34; The 4th cell mount 35; With the framework 36 that these lens hangers and diaphragm frame are housed.
The object lens framework 31 and second cell mount 32, diaphragm frame 33, the three cell mounts 34, and the 4th cell mount 35 has constituted a set of lenses together.The 4th cell mount 35 has a movable coil 35a, and this coil is inserted among the magnet 35b, makes this magnet ring around it.When this movable coil was energized, movable coil 35a and magnet 35b played so-called linear electric motors jointly, so that its integral body moves along optical axis direction.
And second picture frame 32 is supported by linear feeding system 37, and this picture frame is movably with respect to object lens frame 31 on optical axis direction, and propulsion system 37 has the magnetoresistive effect sensor with Fig. 1 or linear feeding system same way as shown in Figure 10 configuration.In the case, magnetoresistive effect sensor 37a is fixing with framework 36, and meanwhile, the nut assembly 37a of this linear feeding system 37 and second picture frame 32 are coupled.
Thus, when the power source of excitation linear propulsion system 37, second picture frame 32 can be moved with respect to object lens 31, the three picture frames 34 and the 4th picture frame 35.
According to the lens barrel of above-mentioned TV camera, object lens frame 31, the second picture frames 32, the three picture frames 34, reaching the 4th picture frame 35 can integrally move along optical axis by suitable excitation movable coil 35a, to focus on action.And, by the power source of suitable excitation linear propulsion system 37, second picture frame 32 can be moved with respect to object lens frame 31, the three picture frames 34 and the 4th saturating frame 35, to realize zoom.
Advance in the system 37 in the linearity that adopts direct current machine to make its power source, each λ can export 4 pulses from magnetoresistive effect sensor, and wherein the diameter of direct current machine is 10mm Φ; The used magnet diameter of magnetoresistive effect sensor is 8mm Φ; The magnetization gap lambda is 200 μ m; Screw pitch is 0.5mm.So according to following formula (6), the position resolution of each pulse can be 1 μ m:
The resolution of each pulse=500/ (8,00 * pi/2 00)=1 μ m on the contrary, if linear feeding system adopts stepping motor same as the prior art and is not with magnetoresistive effect sensor, then the output changeed of 10 teeth will have 20 pulses.The resolution of each pulse is 25 μ m.Compare with the used stepping motor of prior art, adopt linear feeding system of the present invention can improve 25 times of resolution.Therefore can finish propelling accurately.
Thus, the resolution that moves of second picture frame 32 will improve an order of magnitude when carrying out zoom with linear feeding system 37.Thereby can change focusing performance.
According to above-mentioned embodiment, by being fixed in cylindrical on the power source.Alternately arrange the N-utmost point and S-pole field on cylindrical shape or the disc magnet periphery, make this action of a magnetic field, can detect the rotation direction and the speed of power source accurately at magnetoresistive effect sensor facing to magnet.Thereby can move to the desired location place to nut assembly accurately.
And, by one by the magnet that is fixed in the power source rotating shaft; Be positioned the magnetoresistive effect sensor on magnet opposite; The simple structure that processor constituted that is used to handle this magnetoresistive effect sensor output signal just can be measured the rotation direction and the speed of rotating shaft.And, can reduce parts and assembly cost.Simultaneously, this structure can also be done forr a short time.
But, if magnetoresistive effect sensor has a striated structure that can produce midpoint potential in a sine or quasi sine cycle output signal and N-utmost point of magnet or the S-utmost point width, then by calculating the poor of magnetoresistive effect sensor output signal and midpoint potential, can be at an easy rate the rotation of power source be detected.
If magnetoresistive effect sensor has two kinds of striated structures, and 1/4 of N-utmost point of magnet or the S-utmost point width that stagger each other, then can pick out the direction that the power source rotating shaft is rotated at an easy rate.
And, if a comparator that is used for comparison magnetoresistive effect sensor output valve and midpoint potential is arranged, with a controller that is used to detect power source rotation direction and angle, then can measure the rotation of power source at an easy rate, and realize the drive controlling of power source by the edge that detects this comparator output signal pulse.
Lens barrel in the TV camera that is used for having track in mechanism if aforementioned linear feeding system is used as track in mechanism, just can carry out propelled at high velocity in high-precision low cost ground.
In the used camera lens of camera lens zoom propulsive mechanism and lens focus mechanism TV camera is arranged,, then can carry out fast zoom in low-cost and high-precision ground if adopt aforementioned linear feeding system to make camera lens zoom propulsion system.
Therefore, according to above-mentioned embodiment, also can apply to this linear feeding system in the focusing propulsive mechanism.Like this, can improve the speed and the performance of focusing simultaneously.
And, in embodiment shown in Figure 24, also can be with linear electric motors as the zoom motor.Therefore, the prior art ratio with using stepping motor if carry out zoom with linear feeding system of the present invention, then can improve nearly 10 times of speed.
In the above-described embodiment, illustrated that linear feeding system of the present invention is used for the situation on the TV camera lens barrel, but the present invention is not limited only to this.Can be used as linear feeding system of the present invention the axle propulsive mechanism of optical pickocff in the optical detection system, the optical pickocff of this optical detection system can moving radially along CD by means of the axle propulsive mechanism.In this case, optical pickocff can high-precision high-speed ground near the desired location on the CD.And, under lower-cost condition, can shorten greatly near the time, make this system become littler simultaneously.
In addition, linear feeding system of the present invention also is applicable to the printhead propulsive mechanism.In the case, printhead can at full speed move accurately, thereby improves print speed and precision.
As mentioned above, according to the present invention, can provide a kind of small-sized linear feeding system simple in structure, it can low cost carry out the high accuracy propelling at a high speed.
Claims (5)
1. a linear feeding system comprises power source, and one constitutes the screw rod of one with described power source rotating shaft, and is screwed in the nut assembly on the described screw rod, it is characterized in that also comprising:
One is cylindrical, cylindrical shape, or discoidal, be assemblied in the described power source rotating shaft, and the magnet of the alternatively distributed N-utmost point and the S-utmost point is along the circumferential direction arranged;
A magnetoresistive effect sensor that is fixed on described magnet opposite, it has a striated structure, and this striated structure can produce the quasi-sine-wave of one-period and output signal and the midpoint potential that accurate cosine wave forms in the width of a N-utmost point or the S-utmost point;
A comparator that is used for comparison magnetoresistive effect sensor output signal and midpoint potential; And
A controller that is used for detecting described power source rotation direction and angle according to the output signal of described comparator.
2. one kind with the TV camera lens barrel of linear feeding system as track in mechanism, includes power source, constitutes the screw rod of one with described power source rotating shaft and be screwed in nut assembly on the described screw rod, it is characterized in that also comprising:
Along the circumferential direction be alternately distributed the N utmost point and the S utmost point and be fixed on magnet in the described power source rotating shaft; And
Be fixed on the magnetoresistive effect sensor on described magnet opposite.
3. TV camera lens barrel that zoom lens propulsive mechanism and condenser lens propulsive mechanism are arranged, wherein adopt a linear feeding system as its described zoom lens propulsive mechanism, it comprises: power source, with the screw rod of described power source rotating shaft formation one, with the nut that is screwed on the described screw rod
It is characterized in that described linear feeding system comprises:
Cylindrical a, cylindrical shape or a disc magnet that along the circumferential direction is alternately distributed the N-utmost point and the S-utmost point, and it is fixed in the rotating shaft of described power source;
A magnetoresistive effect sensor that is fixed on described magnet opposite, it has output signal and the midpoint potential that the quasi sine that can produce one-period in the width of a N-utmost point or the S-utmost point and accurate cosine wave form;
Be used for the output signal of more described magnetoresistive effect sensor and the comparator of midpoint potential; And
A controller that detects described power source rotation direction and angle according to described comparator output signal.
4. according to the TV camera lens barrel of claim 3, it is characterized in that described power source is a direct current motor.
5. according to the TV camera lens barrel of claim 3, it is characterized in that described power source is a stepping motor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP096971/94 | 1994-04-11 | ||
| JP9697194 | 1994-04-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1121272A CN1121272A (en) | 1996-04-24 |
| CN1050463C true CN1050463C (en) | 2000-03-15 |
Family
ID=14179117
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95105150A Expired - Fee Related CN1050463C (en) | 1994-04-11 | 1995-04-11 | Lens barrel for a video camera, and linear feeding system therefor |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US5602681A (en) |
| KR (1) | KR100373295B1 (en) |
| CN (1) | CN1050463C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109314420A (en) * | 2016-06-09 | 2019-02-05 | Lg伊诺特有限公司 | Rotor assembly, motor and the actuator including the motor |
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| US5900995A (en) * | 1994-11-25 | 1999-05-04 | Canon Kabushiki Kaisha | Driving device and optical apparatus |
| US5926322A (en) | 1997-08-04 | 1999-07-20 | Fuji Photo Film Co., Ltd. | Zoom lens device with zooming position detector |
| GB9716658D0 (en) * | 1997-08-07 | 1997-10-15 | Lucas Ind Plc | Improvements relating to motors |
| JPH1184207A (en) * | 1997-09-09 | 1999-03-26 | Olympus Optical Co Ltd | Optical equipment |
| AT406800B (en) * | 1998-03-09 | 2000-09-25 | Bauer Fritz | CONTROL SYSTEM FOR A LENS OF A CAMERA |
| KR100459694B1 (en) * | 1998-04-08 | 2005-04-06 | 삼성전자주식회사 | How to measure the motor torque constant |
| JP2000078892A (en) * | 1998-08-28 | 2000-03-14 | Matsushita Electric Ind Co Ltd | Driving apparatus of stepping motor |
| DE19857805A1 (en) * | 1998-12-15 | 2000-06-21 | Uwe Plettenberg | Highly dynamic linear unit e.g. for telescope, has ball circulation nut connected directly to motor's rotor or via approximately coaxial hollow shaft gear, and ball circulation spindle passing through nut and rotor |
| US6400142B1 (en) * | 1999-08-31 | 2002-06-04 | Delphi Technologies, Inc. | Steering wheel position sensor |
| GB9921421D0 (en) * | 1999-09-11 | 1999-11-10 | Huntleigh Technology Plc | Position sensor |
| JP4503210B2 (en) * | 2002-01-25 | 2010-07-14 | 株式会社ニコン | Digital still camera |
| EP1955430B1 (en) * | 2005-12-01 | 2012-05-23 | ebm-papst St. Georgen GmbH & Co. KG | Electric motor |
| US7443160B2 (en) * | 2006-09-28 | 2008-10-28 | Wolf Ronald J | Position sensor |
| US7898205B2 (en) * | 2008-06-27 | 2011-03-01 | Hiwin Mikrosystem Corp. | Feedback positioning module |
| US7965010B2 (en) * | 2008-09-03 | 2011-06-21 | Bose Corporation | Linear motor with patterned magnet arrays |
| WO2013050535A2 (en) * | 2011-10-07 | 2013-04-11 | Novo Nordisk A/S | System for determining position of element |
| JP5980010B2 (en) * | 2012-06-27 | 2016-08-31 | キヤノン株式会社 | Driving device, lens barrel, and imaging device |
| JP6364067B2 (en) | 2013-04-05 | 2018-07-25 | ノボ・ノルデイスク・エー／エス | Administration record device of drug delivery device |
| JP6648022B2 (en) * | 2013-09-11 | 2020-02-14 | ボーンズ、インコーポレイテッド | Devices and methods related to high resolution multi-turn sensors |
| US11287600B2 (en) * | 2014-03-18 | 2022-03-29 | Idex Health & Science Llc | Method, apparatus, and computer-readable medium for reduced error in positional repeatability |
| US10323960B2 (en) * | 2014-12-31 | 2019-06-18 | Ingersoll-Rand Company | Method of making sensing mechanism and machine system using same |
| AT520088B1 (en) * | 2017-06-29 | 2019-01-15 | B & R Ind Automation Gmbh | Method for operating a transport device in the form of a long-stator linear motor |
| CN110319782B (en) * | 2018-03-30 | 2021-06-08 | 中强光电股份有限公司 | Projection device, backlash detection system and method thereof |
| CN110546869B (en) * | 2018-10-17 | 2021-05-04 | 炼马机电（东莞）有限公司 | Driving block, linear driver and adjustable appliance |
| JP6960985B2 (en) * | 2019-12-27 | 2021-11-05 | エーエーシー オプティックス ソリューションズ ピーティーイー リミテッド | Imaging device with image stabilization function |
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- 1995-04-11 CN CN95105150A patent/CN1050463C/en not_active Expired - Fee Related
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| US4818939A (en) * | 1986-03-05 | 1989-04-04 | Hitachi, Ltd. | Apparatus for magnetically detecting position or speed or moving body utilizing bridge circuit with series connected MR elements |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109314420A (en) * | 2016-06-09 | 2019-02-05 | Lg伊诺特有限公司 | Rotor assembly, motor and the actuator including the motor |
| CN109314420B (en) * | 2016-06-09 | 2021-08-31 | Lg伊诺特有限公司 | Electric machine |
Also Published As
| Publication number | Publication date |
|---|---|
| KR950035011A (en) | 1995-12-30 |
| US5602681A (en) | 1997-02-11 |
| CN1121272A (en) | 1996-04-24 |
| KR100373295B1 (en) | 2003-05-01 |
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